Respiratory Organs & Human System — NEET Biology MCQs with Solutions
Free NEET Biology Respiratory Organs & Human System MCQs with step-by-step solutions (6 questions). Part of Breathing and Exchange of Gases. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Respiratory Organs & Human System · easy · theory
The functional units of the lung where gas exchange occurs are the:
A. Alveoli ✓ Correct
B. Bronchi
C. Trachea
D. Larynx
Solution: Alveoli are thin-walled, vascularised sacs where diffusion of O₂ and CO₂ takes place.
Q2 — Respiratory Organs & Human System · easy · theory
The organ commonly called the voice box, located at the beginning of the trachea, is the:
A. Epiglottis
B. Pharynx
C. Bronchus
D. Larynx ✓ Correct
Solution: The larynx (voice box) helps in sound production; the epiglottis covers it during swallowing.
Q3 — Respiratory Organs & Human System · medium · theory
Which structure prevents food from entering the trachea (windpipe) during swallowing?
A. Glottis
B. Epiglottis ✓ Correct
C. Diaphragm
D. Pleura
Solution: The epiglottis is a cartilaginous flap that covers the glottis during swallowing, directing food to the oesophagus.
Q4 — Respiratory Organs & Human System · medium · theory
The part of the respiratory pathway that only conducts air (no gas exchange) includes all EXCEPT:
A. Alveoli ✓ Correct
B. Trachea
C. Bronchioles
D. Bronchi
Solution: The conducting zone (nostrils to terminal bronchioles) transports/cleans/moistens air; exchange occurs only in the alveoli.
Q5 — Respiratory Organs & Human System · hard · theory
The double-membrane pleura around the lungs, with pleural fluid between its layers, functions to:
A. Exchange gases
B. Reduce friction and allow smooth lung movement during breathing ✓ Correct
C. Store air
D. Produce mucus for digestion
Solution: Pleural fluid lubricates the lung surface, minimising friction against the thoracic wall during breathing.
Q6 — Respiratory Organs & Human System · hard · theory
Which sequence correctly traces air from outside to the site of gas exchange?
A. Trachea → bronchi → pharynx → alveoli
B. Nostrils → pharynx → larynx → trachea → bronchi → bronchioles → alveoli ✓ Correct
C. Nostrils → larynx → pharynx → bronchi → alveoli → trachea
D. Nostrils → trachea → pharynx → alveoli
Solution: Air passes: external nostrils → nasal chamber → pharynx → larynx → trachea → primary bronchi → bronchioles → alveoli.